Anastrozole promotes implantation by altering the expression of paxillin and fak in rat luminal uterine epithelium / El anastrozol promueve la implantación alterando la expresión de paxilina y fak en el epitelio uterino luminal de rata

An alternative hyper-ovulator inducer to replace clomiphene citrate (CC) is needed as it is unsuitable for women with polycystic ovarian syndrome and is associated with low pregnancy rates. Anastrozole is an effective hyper-ovulator inducer, but has not been well researched. In order to determine the effectiveness of anastrozole as a hyper-ovulator inducer and to an extent compare it with CC in similar situations, this study ascertained the effects of these drugs on the expression of the focal adhesion proteins, paxillin and FAK, which are uterine receptivity markers in the surface luminal uterine epithelial cells of day 1 and day 6 pregnant Wistar rats. The results show that paxillin is localized in focal adhesions at the base of the uterine epithelial cells at day 1 of pregnancy whereas at day 6, paxillin disassembles from the basal focal adhesions and localizes and increases its expression apically. FAK is faintly expressed at the basal aspect of the uterine epithelial cells while moderately expressed at the cell-to-cell contact at day 1 in all groups from where it disassembles and relocates apically and becomes more intensely expressed at day 6 of pregnancy in untreated and anastrozole treated rats. Although paxillin is localized apically at day 6, its expression is significantly down-regulated with CC treatment suggesting its interference with the implantation process. These findings seem to suggest that anastrozole could favor implantation.

Para reemplazar el citrato de clomifeno (CC) es necesario un inductor de hiperovulación alternativo, ya que no es adecuado para mujeres con síndrome de ovario poliquístico y está asociado con tasas bajas de embarazo. El anastrozol es un inductor eficaz del hiper-ovulador, pero no se ha investigado adecuadamente. Con el fin de determinar la efectividad del anastrozol como inductor del hiper-ovulador y, en cierta medida, compararlo con CC en situaciones similares, este estudio determinó los efectos de estos fármacos en la expresión de las proteínas de adhesión focal, paxillin y FAK, uterinas marcadores de receptividad en la superficie luminal de células uterinas epiteliales, del día 1 y día 6 en ratas Wistar preñadas. Los resultados muestran que la paxilina se localiza en adherencias focales en la base de las células epiteliales uterinas en el día 1 del embarazo, mientras que en el día 6, la paxilina se desmonta de las adherencias focales basales y localiza y aumenta su expresión apicalmente. FAK se expresa débilmente en el aspecto basal de las células epiteliales uterinas, mientras que se expresa moderadamente en el contacto de célula a célula en el día 1 en todos los grupos, donde se separa y se reubica apicalmente y se expresa con mayor intensidad el día 6 de la preñez, en pacientes no tratados y tratados. ratas tratadas con anastrozol. Aunque la paxillina se localiza apicalmente en el día 6, su expresión está significativamente disminuida con el tratamiento con CC, lo que sugiere su interferencia con el proceso de implantación. Estos hallazgos sugieren que el anastrozol podría favorecer el proceso de implantación.

Focal adhesion proteins, vinculin and integrin ß5, during early pregnancy in rat uterine epithelial cells: anastrozole favors their normal distribution / Proteínas de adhesión focales, vinculina e integrina ß5, durante el embarazo temprano en células epiteliales uterinas de rata: anastrozol favorece su distribución normal

SUMMARY: An alternative superovulator to replace clomiphene citrate is needed as clomiphene citrate is associated with low pregnancy rates. Anastrozole is an effective superovulator, but it has not been well researched. In order to determine the effectiveness of anastrozole as a superovulator and to compare it with clomiphene citrate in similar situations, this study ascertained the effects of these drugs on the expression of the focal adhesion proteins, vinculin and integrin β5, which are uterine receptivity markers, in the uterine epithelial cells of day 1 and day 6 pregnant Wistar rats. The results show that vinculin and integrin β5 are co-localized at the base of the uterine epithelium at day 1 of pregnancy whereas at day 6, they disassemble from the basal focal adhesions and co-localize and significantly increase their expression apically (p≤0.0001). Moreover, there is a significant difference in the protein expression levels of vinculin and integrin b5 in uterine luminal epithelial cells between untreated (control) and chlomiphene citrate treated rats (p≤0.0001), anastrozole and chlomiphene citrate treated rats at day 6 (p≤0.0001) suggesting the interpretation that anastrozole seems to enhance their expression in order to perhaps assist in the implantation process of the blastocyst. The immunofluorescence experiments agree with the vinculin and integrin β5 gene expression findings in which at day 6 of pregnancy, vinculin and integrin β5 gene expression are significantly upregulated in uterine luminal epithelial cells in the anastrozole treated group relative to the calibrator sample (p≤0.0001). These findings suggest that anastrozole is implantation friendly.

RESUMEN: Es necesario un superovulador alternativo para reemplazar el citrato de clomifeno, debido a que está asociado con bajas tasas de preñez. El anastrozol es un superovulador eficaz, sin embargo es poca su investigación. Con el fin de determinar la efectividad del anastrozol como superovulador y compararlo con citrato de clomifeno en situaciones similares, se determinaron los efectos de estos fármacos sobre la expresión de las proteínas de adhesión focal, vinculina e integrina β5, en marcadores de receptividad uterina en días 1 y 6, en las células epiteliales uterinas de ratas Wistar preñadas. Los resultados muestran que la vinculina y la integrina β5 se co-localizan en la base del epitelio uterino al día 1 de la gravidez mientras que al día 6 se desmontan de las adherencias focales basales, co-localizan y aumentan significativamente su expresión apicalmente (p≤0.0001). Además, existe una diferencia significativa en los niveles de expresión de proteína de vinculina e integrina β5 en células epiteliales luminales uterinas entre ratas no tratadas (control) y tratadas con citrato declomifeno (p≤0.0001), ratas tratadas con anastrozol y citrato declomifeno al día 6 (p≤0,0001) sugiriendo la interpretación de que el anastrozol parece mejorar su expresión con el fin de ayudar en el proceso de implantación del blastocisto. Los experimentos de inmunofluorescencia coinciden con los resultados de la expresión de los genes vinculina e integrina β5 en los cuales al día 6 de la preñez, la vinculina y la integrina β5 están significativamente reguladas en células epiteliales luminales uterinas en el grupo tratado con anastrozol con respecto a la muestra del calibrador (p<0,0001). Estos hallazgos sugieren que el anastrozol es favorable para la implantación.

CD98 activation increases surface expression and clusteringof beta 1 integrins in MCF-7 cells through FAK/Src- and cytoskeleton-independent mechanisms

CD98, a disulfide-linked 125-kDa heterodimeric type II transmembrane glycoprotein, regulates beta 1 integrin- mediated cell adhesion. However, the molecular mechanisms underlying CD98-mediated activation of beta 1 integrin are presently unclear. In this study, the effects of CD98 signaling on the expression and clustering of beta 1 integrin were investigated. Activation of CD98 augmented surface expression of beta 1 integrin on MCF-7 cells. Cross-linking CD98 induced clustering of beta 1 integrins. Inhibition of phosphorylation of focal adhesion kimase (FAK) by PP2, an inhibitor of Src family kinase, reduced cell-extracellular matrix adhesion, but not surface expression and clustering of beta1 integrin on MCF-7 cells. This result was confirmed by over-expression of dominant negative forms of FAK. In addition, phalloidin or cytochalasin D inhibited CD98-mediated induction of cell-ECM adhesion, but not surface expression and clustering of b1 integrins. The inhibitory effects of PP2, cytochalasin D or phalloidin on CD98-stimulated cell adhesion were diminished by pretreatment of cells with Mn2+, which is shown to induce conformational change of integrins. These results provide the first evidence that CD98 activation increases not only beta1 integrin affinity but also its surface expression and clustering and the latter is independent of FAK/Src and cytoskeleton.